1. Field of the Invention
The present invention relates to a multi-part piston for a combustion engine having a piston upper part and a piston lower part. The upper part has an attachment head on its side facing the lower part. The lower part has a support plate with a plate element and an attachment element holding the attachment head, located on a side of the lower part facing the upper part.
2. The Prior Art
Multi-part pistons have the crucial advantage that the piston upper part and the piston lower part can be of different materials. The piston upper part is generally made from a particularly wear-resistant and heat-resistant, but relatively heavy material, while the piston lower part is generally made from a less wear-resistant light metal material in order to reduce its weight. Here, the piston upper part and the piston lower part can be connected to one another by screwing, as disclosed for example in European Patent No. EP 1 483 493 B1.
A generic piston is described in German Patent No. DE 102 57 022 A1. It has a threaded head attached to the piston upper part and a support plate attached to the piston lower part, and has a threaded element matching the threaded head, which are screwed to one another during assembly of the piston.
In diesel engines in particular, pistons are subject to high thermal and mechanical stresses. It is therefore desirable to provide the piston with a good cooling system, i.e. with a cooling channel of the largest possible volume, and with a connection between the piston lower part and the piston upper part that can withstand particularly high mechanical loads. At the same time, the piston should be lightweight and compact. In particular, the compression height should not be too great, in order to keep the cylinder block of a diesel engine in particular as low as possible.